(Yes, that is the actual model number. I have double- and triple-checked. It is not US rather than ZS.)

The oven in my 2003 range will not stay lit. Whether selecting baking or broiling, the oven will light off normally and then shut down within a matter of less than a minute. The oven light then flashes four times, repeating until you turn off the oven. The heating light has not worked for years, so I do not know what the second digit of the error code is, but I assume this is a code 43, cooling fan not working, rather than 44, door latch fault, because (as I understand it), the latter fault would not shut down the oven, but the former would.

I have checked the resistance of the oven thermostat. It was 1086 ohms at room temperature. I believe that is normal. I have checked that the fans come on. They do. I located a "sail" switch (mechanical air flow switch) in front of one blower and checked its operation and continuity. It operates fine. Further, jumping the connectors to the switch (to bypass it) does not solve the problem. (I did not see another sail switch at the other fan. If I missed it, please let me know.) I replaced the very expensive oven control relay board. That had no effect.

What other components should I be checking and where do I find them?